Lucy, a student living in Taiwan, is tricked into delivering a briefcase, resulting in her being kidnapped and having a package containing a dangerous synthetic substance surgically implanted in her body. She is intended to be a vessel for the chemical, but it leaks into her system, unlocking her cerebral capacity to superhuman levels. She races across the world to enlist the help of a brain expert who can help her retain the last vestiges of her humanity. Her ruthless former captors pursue her, killing anyone who stands in their way, but they soon learn that Lucy has transformed into a warrior evolved beyond human logic....